The need to cure multiaxial deviations from the desired section shape arises from the passage of the sections, for example H-beams, U-beams or T-beams, after the rolling onto a cooling bed. There they remain for cooling until they generally reach a temperature of about 60° C. In the preceding rolling process and especially however also during the cooling down, the sections distort both vertically and horizontally and also can twist about their longitudinal axes. As a consequence, apart from geometric nonuniformity in the rolled products, intrinsic stresses can arise in the material which are more clearly indicated in a subdivision of the section.
Through the use of section straightening machines, especially those which have been customary for thick wall sections, a biaxial planar arrangement of straightening rollers or tools above and below the alignment line engage the product to be straightened and are arranged in the transport direction to subject the product to an alternating bending. Tools are comprised as a rule of straightening disks fastened on bushings which are arranged on straightening shafts with the same axes as the tools and with a predetermined pitch or spacing or at a predetermined distance from one another. The alternating bending can result ideally in an improvement of the straightening, in both the vertical and horizontal directions. In this connection, it is known for the straightening of, for example H-beams (see EP D1 0 472 765), to provide at least one of the beam flanges with a straightening disk which is axially adjustable and engages that flange from the inside and is carried by a straightening shaft and in this manner enables variation of the outer dimension or chamber dimension of the flange by the straightening disk.
Since the straightening results for bar material, sections or like rolled beams depend significantly upon the stiffness of the overall straightening machine, the known section straightening machines are comprised of a multipart stand of welded construction or a stand of a combined cast construction and welded construction. The straightening machines which are of purely welded construction are usually so formed that two lateral stands are connected by means of a lower traverse and an upper traverse with one another. In configurations as a cast construction/welded construction, two massive cast beams are connected together by welding.
In a section-straightening machine which has become known from DE 28 23 526 C2, the two lateral stands are arranged at a distance one behind the other in the travel direction of the bar material, these lateral stands being formed by upright stand beams which are mounted in a portal-like manner at the ends of the horizontal stand beam while C-shanks interconnect intermediate posts together at their ends by tension lugs. The basis for this massive construction is to enable it to take up the straightening forces in a closed system. The requirements for straightening precision with this configuration necessitates stiff and massive stand constructions which are material-intensive and thus costly components. The mechanical machining of such components in turn requires that large, expensive and not readily available machine tools be used.